Stator for an electric motor

ABSTRACT

A stator for an electric motor is described. An example stator includes a stator core having teeth that are radially arranged about a common central axis of the stator and located in a spaced apart manner from one another. Each tooth has an inward portion and an outward portion. The example stator further includes an electrically transmissive coil of wire that is wound contiguously upon the inward portions of at least a subset of teeth from the plurality of teeth. The stator also includes wedge members that are radially arranged about the common central axis and located intermittently with the plurality of teeth such that each wedge member abuts with the outward portions of adjacently located teeth.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

This application claims priority to U.S. Prov. App. No. 62/789,274 tiled“STATOR FOR AN ELECTRIC MOTOR” and filed on Jan. 7, 2019, the disclosureof which is hereby incorporated herein by reference in its entirety.

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 CFR 1.57.

BACKGROUND Field of the Invention

The present disclosure relates to an electric motor. More particularly,the present disclosure relates to a stator for an electric motor.

Description of the Related Art

Typical electric motors have stator cores that are formed from metallaminates stacked one above another. An inner periphery of these statorcores typically define slots (or teeth) on which multiple coils of wireare wound. Each coil of wire may be wound over all or a subset of theslots. As the slots are defined only along the inner periphery of thestator core, such winding of the coil of wires over the subset of slotsin the stator core may be challenging, laborious and hence, timeconsuming. Moreover, such winding may incur additional expense in termsof tooling requirements that are required to perform the winding ofcoils in the slots of the stator core.

SUMMARY

One embodiment includes a stator for an electric motor. The statorcomprises a stator core having a plurality of teeth radially arrangedabout a common central axis of the stator core and located in a spacedapart manner from one another, each tooth having an inward portion andan outward portion; an electrically transmissive coil of wire woundcontiguously upon the inward portions of at least a subset of teeth fromthe plurality of teeth; and a plurality of wedge members radiallyarranged about the common central axis and located intermittently withthe plurality of teeth such that each wedge member abuts with theoutward portions of adjacently located teeth.

Another embodiment includes an electric motor comprising a stator. Thestator comprises a stator core having a plurality of teeth radiallyarranged about a common central axis of the stator core and located in aspaced apart manner from one another, each tooth having an inwardportion and an outward portion; an electrically transmissive coil ofwire wound contiguously upon the inward portions of at least a subset ofteeth from the plurality of teeth; and a plurality of wedge membersradially arranged about the common central axis and locatedintermittently with the plurality of teeth such that each wedge memberabuts with the outward portions of adjacently located teeth.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a stator that is used to form an electric motor,according to certain embodiments of the present disclosure.

FIG. 2 illustrates a top perspective view of a stator core showing aplurality of teeth in arranged in a spaced apart manner and locatedradially about a common central axis of the stator core for forming thestator of FIG. 1 , according to certain embodiments of the presentdisclosure.

FIG. 3 illustrates a top view of the stator core in which the teeth arewound with an electrically transmissive coil of wire, according tocertain embodiments of the present disclosure.

FIG. 4 illustrates a top view of the stator core shown assembled withmultiple wedge members to form the stator of FIG. 1 , according tocertain embodiments of the present disclosure.

FIG. 5 illustrates a top view of the stator of FIG. 1 showing an end caphaving connecting terminals that can be used to electrically connectwith the electrically transmissive coil of wire, according to certainembodiments of the present disclosure.

FIG. 6 illustrates a side perspective view of the stator showing a bandthat is used to secure the wedge members, according to certainembodiments of the present disclosure.

FIG. 7 illustrates a sectional view of the stator taken along sectionalplane AA′ of FIG. 6 , according to certain embodiments of the presentdisclosure.

FIG. 8 illustrates a side perspective view of the stator core showntogether with an exemplary assembling tool for retaining the teeth whilethe teeth are wound with the electrically transmissive coil of wire,according to certain embodiments of the present disclosure.

Embodiments of the present disclosure and their corresponding advantagesare best understood by referring to the detailed description thatfollows. It should be appreciated that like reference numerals are usedto identify like elements illustrated in one or more of the figures,wherein drawings shown are for purposes of illustrating embodiments ofthe present disclosure and not for purposes of limiting the same.

DETAILED DESCRIPTION

FIG. 1 illustrates a stator 102 that is used to form an electric motor100 in accordance with certain embodiments of the present disclosure.The electric motor 100 formed can be a direct current motor that ispowered using a direct current (DC) source (not shown) or may be poweredby an alternating current (AC). In embodiments, the electric motor 100is an alternating current inductive motor. The stator 102 may be rigidlyheld within a housing (not shown) of the electric motor 100. Theelectric motor 100 also includes a rotor (not shown) located within anannular hole 116 defined by the stator 102. In operation, the rotor isdriven by the electromagnetic force generated by the stator 102.

Referring to FIGS. 1-4 , the stator 102 includes a stator core 104. Thestator core 104 has multiple teeth 106 that are individually denoted byreference numerals ‘106 a’, ‘106 b’, ‘106 c’, ‘106 d’ and so on(hereinafter collectively denoted by reference numeral ‘106’). Theseteeth 106 are radially arranged about a common central axis XX′ of thestator core 104 and located in a spaced apart manner from one another.Further, each tooth 106 has an inward portion 108 and an outward portion110. Moreover, as shown, the annular hole 116 defined by the stator core104 may be located between ends 118 of the respective inward portions108 of the teeth 106.

The stator 102 also includes an electrically transmissive coil of wire112 which is wound contiguously upon the inward portions 108 of at leasta subset of teeth from the plurality of teeth 106. For example, a singlecoil of wire 112 may be wound upon the subset of teeth 106 comprising ofindividual tooth 106 a, 106 b, 106 c, and 106 d. Although the subset ofteeth 106 disclosed herein comprises four teeth (e.g., teeth 106 a, 106b, 106 c, and 106 d), in other embodiments, fewer or more teeth 106 maybe included to form the subset of teeth 106 from amongst the teeth 106present on the stator core 104.

The stator 102 further includes multiple wedge members 114. These wedgemembers 114 are radially arranged about the common central axis XX′ andlocated intermittently with the teeth 106 of the stator core 104 suchthat each wedge member 114 abuts with a pair of outward portions 110 ofadjacently located teeth 106.

In a certain embodiment, the end 118 of the inward portion 108 of eachtooth 106 defines a pair of ledge members 120 a, 120 b that extendlaterally from the tooth 106 and define an opening (with a width ‘W1’)between them. These ledge members 120 a, 120 b help produce the desiredmagnetic field to drive a rotor of the electric motor. In embodiments,the width ‘W1’ is less than the width of the wire such that the wirecannot be inserted from the inner portion of the stator. In embodiments,the width ‘W1’ between the ledge members 120 a, 120 b is zero. That isthe teeth are connected. In embodiments, adjacently located teeth 106are spaced apart from one another by a pre-determined distance ‘D’.

In embodiments, each wedge member 114 comprises a radially inwardportion 122 proximal to the common central axis XX′ and a radiallyoutward portion 124 distal from the common central axis XX′. A width‘W2’ of the radially outward portion 124 is greater than a width ‘WJ’ ofthe radially inward portion 122. Furthermore, an end 126 of the radiallyoutward portion 124 of each wedge member 114 is configured to allowapplication of a compressive load ‘C’ directed radially inward towardsthe common central axis XX′ such that the wedge members 114 frictionallyengage with the teeth 106 for restricting relative movement between theteeth 106. In a certain embodiment, the end 126 of the radially outwardportion 124 of each wedge member 114 defines a recessed portion 128 thatextends partway along the width ‘W2’ of the radially outward portion124. In this embodiment, the recessed portion 128 defined on the wedgemember 114 may be used for applying the compressive load ‘C’ directedradially inward towards the common central axis XX′ by allowingengagement with a compression tool (not shown).

In certain embodiments, the teeth 106 and the wedge members 114 may bemade from a similar material. In other embodiments, the teeth 106 andthe wedge members 114 may made from dissimilar materials. Materials usedto form the teeth 106 and the wedge members 114 respectively may beselected based on various requirements of an application including, butnot limited to, thermal requirements besides electrical conductivity,electrical transmittance, and/or resistivity desired from the teeth 106and the wedge members 114 respectively.

Referring to FIGS. 1 and 5 , in certain embodiments, an end cap 502 isdisposed about the central axis XX′ and affixed onto one side of thestator core 104. The end cap 502 has connecting terminals 504 a, 504 b,and 504 c for electrically connecting with ends (not shown) of theelectrically transmissive coil 112. Further, as shown best in the viewof FIG. 6 , a band 602 may be disposed about the wedge members 114 tosecure the wedge members 114 with the stator core 104. This band 602 mayextend along a height ‘H’ of the stator core 104. Furthermore, this band602 may be formed from a metal, a composite, or a polymer. As shown bestin the view of FIG. 7 , the band 602 may also serve to apply thecompressive load ‘C’ for retaining the wedge members 114 in theirrespective positions and preventing inter-relative movement between theteeth 106.

In certain embodiments, each tooth 106 may be a monolith (e.g., eachtooth 106 may be singularly formed to the height ‘H’ of the stator core104). However, in certain other embodiments, each tooth 106 may bestratified along the height ‘H’ of the stator core 104. In suchembodiments, each tooth 106 may comprise at least two teeth members (notshown) that are stacked in a direction ‘D1’ parallel to the commoncentral axis XX′. For instance, each tooth 106 may comprise multiplemetal laminations (e.g., 50 or 100 laminations which are stacked alongthe direction ‘D1’).

In some embodiments herein, the teeth 106 of the stator core 104 may bearranged radially about the common central axis XX′ and located in aspaced apart manner from one another. Such arrangement and location ofthe teeth 106 imparts a segmented configuration to the stator core 104that allows manufacturers of electric motors to implement tooling, forexample, an assembling tool 802 as shown in the view of FIG. 8 forholding the individual tooth 106 of the stator core 104 via theirrespective ledge members 120 a, 120 b. Additionally, manufacturers couldalso implement other tooling mechanisms that could easily wind the coilof wires 112 over the teeth 106 of the stator core 104, preferably, fromoutside the stator core 104 towards the ledge members 120 a, 120 b ofeach tooth 106 until the coil of wires 112 stacks up on the ledgemembers 120 a, 120 b. As access from outside the stator core 104 isestablished with implementation of embodiments herein, manufacturers ofthe electric motors 100 disclosed herein can offset costs, time, andeffort that were incurred with traditional practices of winding coils ofwires from the inside out. (e.g., radially outward from a central axisof previously designed stator cores in which access from an innerdiameter to an outer diameter of the stator core 104 would not bepermitted due to the presence of a bulk of the stator core 104 betweenthe inner and outer diameters of the stator core 104).

As access to tooling is provided from outside the stator core 104,winding may be easily and quickly accomplished. Thereafter, the wedgemembers 114 may be inserted in a radially inward direction betweensuccessive teeth 106 of the stator core 104 to frictionally engage withthe outward portions 110 of the teeth 106. Once engaged, the wedgemembers 114 help secure the teeth 106 by preventing an inter-relativemovement between the teeth 106. Compressive load ‘C’ may be applied tothe ends 126 of the wedge members 114 to frictionally engage the teeth106. Also, when the band 602 is used, the band 602 may also servecontinue applying the compressive load ‘C’ for retaining the wedgemembers 114 and securing the teeth 106 in their respective positions.

The foregoing disclosure is not intended to limit the present disclosureto the precise forms or embodiments disclosed herein. As such, it iscontemplated that various alternative forms, embodiments and/ormodifications to the present disclosure, whether explicitly described orimplied herein, are possible in light of the disclosure. Having thusdescribed embodiments of the present disclosure, a person of ordinaryskill in the art will recognize that changes may be made in form anddetail without departing from the scope of the present disclosure.

In the foregoing specification, the disclosure has been described withreference to specific embodiments. However, as one skilled in the artwill appreciate, various embodiments disclosed herein can be modified orotherwise implemented in various other ways without departing from thespirit and scope of the disclosure. Accordingly, this description is tobe considered as illustrative and is for the purpose of teaching thoseskilled in the art the manner of making and using various embodiments ofthe disclosed battery system. It is to be understood that the forms ofdisclosure herein shown and described are to be taken as representativeembodiments. Equivalent elements, or materials may be substituted forthose representatively illustrated and described herein. Moreover,certain features of the disclosure may be utilized independently of theuse of other features, all of which is apparent to one skilled in theart after having the benefit of this description of the disclosure.Expressions such as “including”, “comprising”, “incorporating”,“consisting of”, “have”, “is” used to describe and claim the presentdisclosure are intended to be construed in a non-exclusive manner,namely allowing for items, components or elements not explicitlydescribed also to be present. Reference to the singular is also to beconstrued to relate to the plural.

Further, various embodiments disclosed herein are to be taken in theillustrative and explanatory sense and should in no way be construed aslimiting of the present disclosure. All joinder references (e.g.,connected, affixed, and the like) are only used to aid the reader'sunderstanding of the present disclosure, and may not create limitations,particularly as to the position, orientation, or use of the elementsdisclosed herein. Therefore, joinder references, if any, are to beconstrued broadly. Moreover, such joinder references may not necessarilyinfer that two elements are directly connected to each other.

It will also be appreciated that one or more of the elements depicted inthe drawings/figures can also be implemented in a more separated orintegrated manner, or even removed in certain cases, as is useful inaccordance with a particular application.

What is claimed is:
 1. A stator for an electric motor, the statorcomprising: a stator core having a plurality of teeth radially arrangedabout a common central axis of the stator core and located in a spacedapart manner from one another, each tooth having an inward portion andan outward portion; an electrically transmissive coil of wire woundcontiguously upon the inward portions of at least a subset of teeth fromthe plurality of teeth; a plurality of wedge members radially arrangedabout the common central axis and located intermittently with theplurality of teeth such that each wedge member abuts with the outwardportions of adjacently located teeth; and a band disposed about radiallyoutward portions of the wedge members, wherein an end of radiallyoutward portion of each wedge member defines a recessed portionextending partway along the width of the radially outward portion,wherein the band applies a compressive load on the recessed portionsdirected radially inward towards the common central axis of the statorcore such that the plurality of wedge members frictionally engage withthe plurality of teeth for restricting relative movement between theplurality of teeth, wherein an end of the inward portion of each toothdefines a pair of ledge members extending laterally from the tooth whichdefine an opening of a first width, wherein the first width indicates awidth between a first ledge member extending laterally from the toothand a second ledge member extending laterally from an adjacent tooth,wherein the first width is less than a second width of the electricallytransmissive coil of wire, and wherein outward portions of adjacentlylocated teeth are spaced apart from one another by a pre-determineddistance.
 2. The stator of claim 1, wherein adjacently located teeth arespaced apart from one another by a distance that is less than the secondwidth.
 3. The stator of claim 1, wherein each tooth is stratified alonga height of the stator core and comprises at least two teeth membersstacked in a direction parallel to the common central axis.
 4. Thestator of claim 1, wherein each wedge member comprises a radially inwardportion proximal to the common central axis and the radially outwardportion distal from the common central axis.
 5. The stator of claim 4,wherein a width of the radially outward portion is greater than a widthof the radially inward portion.
 6. The stator of claim 1, wherein theplurality of teeth and the plurality of wedge members are made from asimilar material.
 7. The stator of claim 1, wherein the plurality ofteeth and the plurality of wedge members are made from dissimilarmaterials.
 8. An electric motor comprising: a stator comprising: astator core having a plurality of teeth radially arranged about a commoncentral axis of the stator core and located in a spaced apart mannerfrom one another, each tooth having an inward portion and an outwardportion; an electrically transmissive coil of wire wound contiguouslyupon the inward portions of at least a subset of teeth from theplurality of teeth; and a plurality of wedge members radially arrangedabout the common central axis and located intermittently with theplurality of teeth such that each wedge member abuts with the outwardportions of adjacently located teeth; and a band disposed about radiallyoutward portions of the wedge members, wherein an end of the radiallyoutward portion of each wedge member defines a recessed portionextending partway along the width of the radially outward portion,wherein the band applies a compressive load on the recessed portionsdirected radially inward towards the common central axis of the statorcore such that the plurality of wedge members frictionally engage withthe plurality of teeth for restricting relative movement between theplurality of teeth, wherein an end of the inward portion of each toothdefines a pair of ledge members extending laterally from the tooth whichdefine an opening of a first width, wherein the first width indicates awidth between a first ledge member extending laterally from the toothand a second ledge member extending laterally from an adjacent tooth,wherein the first width is less than a second width of the electricallytransmissive coil of wire, and wherein outward portions of adjacentlylocated teeth are spaced apart from one another by a pre-determineddistance.
 9. The electric motor of claim 8, wherein adjacently locatedteeth are spaced apart from one another by a distance that is less thanthe width of the coiled wire.
 10. The electric motor of claim 8, whereineach tooth is stratified along a height of the stator core and comprisesat least two teeth members stacked in a direction parallel to the commoncentral axis.
 11. The electric motor of claim 8, wherein each wedgemember comprises a radially inward portion proximal to the commoncentral axis and the radially outward portion distal from the commoncentral axis.
 12. The electric motor of claim 11, wherein a width of theradially outward portion is greater than a width of the radially inwardportion.
 13. The electric motor of claim 8, wherein the plurality ofteeth and the plurality of wedge members are made from a similarmaterial.
 14. The electric motor of claim 8, wherein the plurality ofteeth and the plurality of wedge members are made from dissimilarmaterials.